a. Field of the Invention
The present invention pertains generally to wireless communication networks and specifically to wireless networks with roaming of mobile devices.
b. Description of the Background
Wireless networks face natural limits on the bandwidth and coverage that can be offered to users. Because a given radio has a limited amount of bandwidth, a network may provide a high bandwidth service over a small area for a few users, or a low bandwidth service over a large area for many more users. As the bandwidth requirements increase, the cell size correspondingly decreases.
For mobile applications, a user or subscriber may move from one area or cell covered by a first radio to a second area covered by a second radio. As the user moves to the new area, communications are handed off to the second radio. With large cells or coverage areas, the movement from one cell to another cell may occur slowly enough that a handoff sequence may happen over one or several seconds.
In today's marketplace, the increase in bandwidth is driving cell sizes smaller to the point where the handoff sequences may be too burdensome to implement.